Реакция #682196

Уравнение реакции

HCl

n-Butyllithium

diisopropylamine

LDA

2,4,5-trifluorobromobenzene

dry ice

→

3-bromo-2,5,6-trifluorobenzoic acid

Выход 52.3%

Растворители

THF

THF

diethylether

Условия реакции

Обработка

1. 1
   workup.STIRRINGThe solution was stirred for 10 min
2. 2
   ДругоеThe phases were separated
3. 3
   Экстракцияthe organic layer extracted with 0.5M NaOH
4. 4
   Экстракцияextracted with diethylether
5. 5
   СушкаThe combined organic phases were dried over sodium sulfate
6. 6
   Другоеevaporated

Методика

Step (i) n-Butyllithium (2.5M in hexane, 10.5 mL, 1.1 eq.) was added dropwise over 15 min to a solution of diisopropylamine (4.0 mL, 1.2 eq.) in THF (25 mL) at 0° C. After stirring for 15 min, the LDA solution was added dropwise over 40 min to a solution of 2,4,5-trifluorobromobenzene (5.0 g, 24 mmol) in THF (50 mL) at −78° C. The solution was stirred for 10 min and then transferred to a slurry of dry ice (50 g) in diethylether (65 mL). The reaction was allowed to warm to rt and treated with 1M HCl. The phases were separated and the organic layer extracted with 0.5M NaOH. The basic extracts were acidified to pH 1 with 6M HCl and extracted with diethylether. The combined organic phases were dried over sodium sulfate and evaporated to yield 3-bromo-2,5,6-trifluorobenzoic acid as a white solid (3.2 g, 52%). Step (ii)

Источник